Balanced fluid clutch



Nov. 28, 1950 A. D. RoBBlNs 2,531,744

` BALANCED FLUID CLUTCH Original Filed Nov. 18, 1943 z? /8 17 24 2s Z/ 3l Z9 y /6 0 'r' Y 48 6c/J2 I 39 [3A I8 37 fllllm 40 47 46 M ,9 i 44 v [5, V1x2 IN V EN TOR.

Patented Nov. 28, 1950 UNITED STATES PATENT OFFICE Divided and this application March 15, 1946, Serial No. 654,604

(Cl. lim-85) 6 Claims.

The present invention relates to clutches for transmissions of the type used in motor vehicles, it is a division of a copending application for a patent in transmissions Serial No. 510,711, led November 18, 1943, and embodies more specically an improved clutch construction by means of which a predetermined desired number of speed changes may be affected in a transmission by consecutively engaging a series of said friction clutches, one for each train of gears.

A primary object of the invention is to provide compact and powerful clutches by means of which various gears may be coupled in driving engagement with the shafts on which said gears and clutches are mounted, or the gears may be released to turn freely on said shafts.

Further objects of the invention will appear hereinafter as it is described in detail and in connection with the accompanying drawing in which Figure 1 is a view showing a section through a clutch constructed in accordance with the present invention. Fig. 2 is a view partly in section through Fig. 1 generally on line I-JL Fig. 3 shows a portion of the shaft on which the clutch parts are mounted. Fig. 4 shows an operating arm, or bell crank which also has formed on it a counterweight. Fig. 5 shows one of the friction shoes used in the clutch. Fig. 6 shows an assembly of the shaft as in Fig. 3 but carrying the shoes and operating arms or as would be seen in Fig, 2, viewed from above, with the friction drum removed.

Referring to Fig. 1, the shaft II is adapted to be rotatively connected to the engine of an automobile and is mounted inan antifriction bearing I 2. A second shaft I3 is mounted in axial alignment with shaft I E and shaft II carries an antifriction bearing lf3, supporting the shaft I3 by means of extension I5 on shaft I3.

Shaft 23 has two pairs of radial arms one pair of which is indicated by the numerals I5 and the other pair indicated by the numerals I'I. These arms form supports for the shoes I8. Said arms le and Il have eyes I9 and said shoes I8 have eyes El) to receive clevis pins 2l which pass through the eyes I3 and 2li to attach said shoes to said arms. The shoes I3 also have eyes 22 to provide attachment to links 23. The links 23 have forked ends 24 with eyes 25 to receive clevis pins 26 which pass through eyes 22 of the shoes and eyes 25 of said links.

Referring to Fig. 4 which shows a bell crank comprising a hub 2l from which radiates an arm 28 terminating in forked ends 29, this hub is mounted between arms I6 andzpivoted on pin 2l. The pair of arms I6 are spaced wide enough apart to permit the hub 2l and the eye 23 of one of shoes I8 to be mounted between said arms with the common axis of pin 2 I. The link 23 has an eye 31 adapted to fit between the forked ends 29 of said arms 23 and said link 23 and said arm are pivotally connected by clevis pin 32,.

` Referring to Fig. 6 it will be noted that the hub 2'! and the eye 2B of one of shoes I8, when mounted in the arms i6, the arm 28 is offset so that space between forked ends 29, an eye 3l of link 23 and the central plane of one of shoes I8, are all in a plane substantially as shown by line 8 3 of Fig. 6.

Another operating arm 33 is carried between the pair of arms Il and mounted on pin 34. This operating arm is similar to that shown in Fig. 4 and has a hub 35 but the arm 33 is offset in the opposite direction to arm 28. The space between the forks 36 of arm 33, the eye 3! of another of said links 23 and another of shoes i8 are in a plane shown as line 9-9 of Fig. 6. The shoe I8 is pivotally supported by eye 2D on pin 35 and said shoe is connected by eye 22 to another link 23 by a pin 26.

The shaft I3 has a transverse cylindrical bore 3i located between the pairs of arms I6 and I1. Within said bore are pistons 33 positioned in opposed pairs. The pistons are free to move outwardly in said bore but are limited in their inward movement by an annular ring centrally jection fits closely within the bore 45. On shaft located in said bore. The pistons each have an outwardly projecting boss i2 adapted to abut against one of the forked ends 24 or 36 of the operating arms 28 or 33.

At the end of shaft I I is a gear i3 which serves as a flange to which is attached a drum 34 adapted to rotate with said shaft. The extension I5 of shaft I3 has a central bore 45 adapted to receive a projection 45 from shaft II. This prol I is carried a non-rotative collar il with an opening 48 in the plane of an opening 49 in .shaft I I. Opening 4S communicates with a passage 50, centrally positioned in shaft II. This passage extends through projection 43 and communicates with bore 45 in shaft I3 eventually leading to cylindrical bore 3l. The opening 48 of collar 41 is adapted to receive a tting, not shown, through which uid, preferably oil, may be forced.

It will now be seen that if fluid, under pressure, is forced into the cylindrical bore 31, the pistons 39 will be force outward against the forked ends of arms 28 and 33 thereby forcing both arms and the links 23, outward thereby causing a toggle force applied to separate the eyes and 22,V ,Wilh expand the shoe suflicient to make contact'with the drum.

From each of hubs 2l or tdthere extends a counterweight 52 which is positioned sov that,

when shaft i3 is rotated, centrifugal force, which;

tends to move said counterweight away from the center of the shaft, will move arms 28er 33,

inward and through links 23 draw eyes 22 tangentiallytowardV eyes lwofhoes ylil-and. movement in this-direction will contract the diameter of-said shoes;k If no oounterweight wereprovided, rotationxofshaft I3 would, by centrifugal force, expand shoesV le and at high speeds `would interfere-.with disengaging said shoes `from 'frictional engagementwith said. drum. By using a suit-V able size-of counterweight the centrifugal forces offboth weight and shoe may be balanced and the forces-required to release saidshoes from-frictional engagement will not'be affected by the speed of rotation.

In order tofrelease theshoes i 8 from frictional engagement with the drum 44, springs 53 are interposedbetween shaft i3 andcounterweights 52; When hydrostatic pressure is removedfrom` pistons 39, said springs move said counterweights-v outward andoperating througharms 28 andV 33,

contract'said shoes and also force the pistons 39.

to. their inward` position.

Itwill be seen from-.the-foregoing that the' elements describedcomprise a clutch which, through lnldrostatic` pressure can be made to provide powerfulfrictional engagement between the shoes I8 and the drum lid, Jthereby frictionally locking shafts i i and i3 in driving engagement.

It should be pointed out that this forms a compactclutch. with the operating forces well balanced, placing twol pistons inthe single bore 3l makes possible the.4 balancing of the outward thrust of one pistonand links against the outward thrust of the other piston and links.

While l `have shown the preferred form of my invention is to be considered in an illustrative and not in a limiting sense, .and many changes may be made without departingv from the spirit of. the invention as set forth in the followingY claims.

Iclaim.:

i.. Afriction clutch comprising a shaft, a friction drum in. axial alignment withsaid shaft, said shaft having a radial bore within said drum, a. eftrahsverse arms carried by said, shaft and having eyes at their outer ends, a flexible arcuate shoe having eyes at each end of its are length, a pin mounted through the eyes of said arms and one ofthe eyes of said shoe, an angularly movable arm pivotally mounted on said pin, a link pivotally connecting said arm to the other eye of said shoe, a piston within said radial bore adaptedto move. said movable arm outwardly, said movable arm and said link being positioned toexpand said shoe when said arm is moved ,out-v ward and said shaft havingl a Apassage to admit fluid under hydrostatic pressure to said `radiali bore:

2. A friction clutch comprising a shaft, a friction drum in axial alignment with said shaft, said shaft having a radial bore within said drum, a pair of transverse arms carried by said shaft and having eyes at their outer ends, a flexible arcuate shoe within said drum having eyes at each end of its arc length, a pin mounted through the eyes ofsaid arms and one of the eyes of said shoe, an `angularly movable arm pivotally mounted on said pin, a link pivotally connecting said movable arm to the other eye of said shoe, a piston withinsaid radial bore adapted to move said movable arm outwardly, said movable arm and said link `being positioned to expand said shoe when said arm is moved outward, said shaft having a passage to admit :duid under hydrostatic pressure to said, radial bore,.said movable arm having a counterweight rigidly fixed thereto and positioned to counterbalance centrifugal force tending to expand said shoe.:

3. A friction clutch comprising a-shaft, afriction drum in alignment with said shaft, said shafthaving a vradial bore within said drum, a.. pairf olf-transverse arms carried by said shaft,` al flexible arcuate. shoey pivotally mounted at one'. end between said transverse arms, an angularlymovable arm havingV one end pivotally mountedA between said transverse arms and having its movableY end Voperatively connected to the other end... of saidshoe, a-,piston-within-said radial-bore-` adapted to move said angularly movabley arm andsaid shafthaving a passage to admit fluid under hydrostatic pressure` to said radial bore.

4. A friction clutch .comprising a shaft, a friction. drum in axial. alignment with. said shaf.t,. said shaft having atransverse bore within said drunna pair of transverse arms carried by said shaft, ,a flexible arcuate shoe pivotally mounted,- at onev of itsends between said transverse arms, an angularly movable arm pivotally mounted ,be-.- tweensaid.. transverse arms, a link connecting saidimovablearm to the other end of said; shoe, asecond pair of vtransverse arms carried by saidA shaft andopposite the rst named transverse arms, a` second iexible arcuate shoe pivotally mounted at one of itsends between said secondi pair, of .transverse arms, a second link connecting said ,second movable arm to the other. end-1 of said second shoe, said movable arms andsaid. links. being positioned to expand said shoes when. said arms are moved outward, a pair of pistons in.. said transverse bore and adapted .to Vforce saidt movablearms outward and said shaft having; a passage to. admit iiuid under hydrostatic pressure., between said pistons.

5. A friction clutch comprising a shaft, a frictionwdrumin axialalignment with said shaft, said lshaft havingatransverse bore, apair ofv transverse arms-extending-from saidshaft,y aI flexible arcuate shoe pivotally mounted at one of its ends. between said transverse arms, an angularly movable arm pivotally mounted in said v.transverse arins, a linkV connecting said movable arm tothe other end of said shoe, a second -pair'of transverse arms carried by said shaftt and opposite the first named transverse arms, a, second flexible arcuate shoe pivotally mounted# at one of its ends between said second pair of: transverse arms, a second angularly movable arm pivotally mounted'in saidsecond pair of transverse arms, a second link connecting said second movable armto the other end of said second shoe, a pair oi plungers in said transverse" bore and' means adapted-to4 force said plungers outward `ragainst said movable arms.

6. A friction clutch comprising a shaft, a friction drum, in axial alignment with said shaft, said shaft having a transverse bore within said drum, a pair of transverse arms carried by said shaft and having eyes at their outer ends, a flexible arcuate shoe having eyes at each end of its are length, a pin mounted through the eyes of said transverse arms and one of the eyes of said shoe, an angularly movable arm pivotally mounted on said pin, a link pivotally connecting said movable arm to the other end of shoe, a second pair of transverse arms carried by said shaft and having eyes at their outer ends a second flexible arcuate shoe having eyes at each of its are length, a second pin mounted through the eyes of said second pair of transverse arms and one of the eyes of said second shoe, a second angularly movable arm pivotally mounted on said second pin, a second link pvotally connecting said second shoe, pistons Within said transverse bore and adapted to move said movable arms, and said movable arms axially oiset from their pivoted supports to their point of contact with said pistons.

AZO-R D. ROBBINS.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

